Natalie Portman said she experienced "sexual terrorism" at the age of 13 after the release of her first film.

The Hollywood actress was speaking at the Los Angeles Women's March yesterday about how she felt "unsafe" around men after starring in Leon: The Professional - a movie about a young girl who befriends a hitman to avenge her parents' deaths.

Portman said that the first piece of "fan mail" she received was from a man detailing his "rape fantasy" involving her.

She said:

"A countdown was started on my local radio show to my 18th birthday - euphemistically the date that I would be legal to sleep with.

"Movie reviewers talked about my budding breasts in reviews. I understood very quickly, even as a 13-year-old, that if I were to express myself sexually I would feel unsafe and that men would feel entitled to discuss and objectify my body to my great discomfort."

Portman went on to say that she was forced to reject roles that involved kissing or scenes that could be interpreted as sexual.

The said this led to her being seen in the industry as "prudish, conservative, nerdy, serious."

"At 13 years old, the message from our culture was clear to me. I felt the need to cover my body and to inhibit my expression and my work in order to send my own message to the world that I'm someone worthy of safety and respect.

"The response to my expression, from small comments about my body to more threatening deliberate statements, served to control my behaviour through an environment of sexual terrorism."